


SMUTFIC: Summer Sauna Fun

by TacitlyLeaps



Series: EXPLICIT: Tacit's Lewds, Undertale [2]
Category: Undertale (Video Game)
Genre: Adopted Sibling Incest, Anal Sex, Collar, Corruption, Demon Asriel, Desperation Play, Edgy Asriel, Erotic magic, Face-Fucking, Foot Fetish, God of Absolute Hyperdeath, Humiliation, Kinky, Kinky sex, Liquorice, M/M, Master/Pet, Multiple Orgasms, Not good for the SOUL, Oral Sex, Orgasm Delay/Denial, Perverse Magic, Rough Oral Sex, Sauna, Smut, Sweat, Tongue Fetish, Transformation, WORSHIP!, Write Drunk Edit Sober, Write Drunk Let Your Friends Edit 7 Hours While You Sober Up, musk, sauna sex
Language: English
Status: Completed
Published: 2015-12-27
Updated: 2015-12-27
Packaged: 2018-05-09 15:55:14
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 13,941
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5546126
Author URL: https://archiveofourown.org/users/TacitlyLeaps/pseuds/TacitlyLeaps
Summary: <blockquote class="userstuff">
              <p>The now-adult Asriel and Frisk are spending some quality vacation time at a lakeside summer cabin and things get kinky because Asriel can't handle some brotherly banter like an adult. Cue Asriel slipping into his edgy God of Hyperdeath form to torment Frisk throughout the night. </p><p>Things get really weird. It might be a good life decision to check the tags before reading further. </p><p>You have been warned.</p>
            </blockquote>





	SMUTFIC: Summer Sauna Fun

**Author's Note:**

> Originally published on /utg/ - Undertale General via Pastebin.
> 
> A massive thanks to Motif (/users/motif) for doing a lot of editing work and being an all-around great guy to be around with.

Frisk was relaxing at the very end of the wooden pier, arms folded under his neck, soaking his calves in the warm water. The pier was bobbing gently, the sun was warming up his skin, the human listening to the happy chirps of all the birds of the forest. It was a very warm summer day with barely a cloud in the sky. A perfect day to be at the Dreemurrs' lakeside cabin.

All four of them had agreed to spend some quality vacation time at the remote cabin, safely tucked away from the worries and the hurries of the world. Asgore had scouted the place some years ago while visiting the Nordic country and had promptly purchased the place. A nice summer resort, far from their actual home, cellphone barely able to get a signal there.

Asgore and Toriel were still busy with some diplomatic meetings in the capital. Asriel and Frisk had arrived to the summer cabin to get everything ready and stuff like that, the two young adults more than capable of surviving a week there without the supervision of their parents.

Frisk had to admit that his dad had a great eye for comfy. A two-story wood cabin, a stone's throw away from a nice, clean lake surrounded by a lush, green forest. The lot had other buildings as well, including a storage shack full of firewood and tools, a smaller cabin with space for two people to sleep in and a nice sauna even closer to the lake.

It was getting so cozy on the pier that he nearly fell asleep. All he had on was his shorts and wifebeater, leaving ample amounts of skin to get a sunburn on if he couldn't fight off the impending sleepiness. Thankfully, the sound of his brother's panting and heavy footsteps cleared up his mind, the slender human yawning as he listened to Asriel getting closer.

Asriel had really gotten into exercising in the past few months. He was returning from a jog through a forest path, the wind already carrying the smell of his sweaty fur to Frisk's nose. Soon he could hear his padded feet pat against the pier's wooden boards, the goat fighting to get his breathing under control. The pier sunk a little more as Asriel moved towards Frisk.

A shadow loomed over Frisk's head. He opened his eyes, looking up at Asriel who had decided to stand above him, Frisk's head between his legs. He was looking down at his human brother with a warm smile, fur matted with sweat, blotches of moisture darkening the fabric of Asriel's shorts and t-shirt. “Howdy, lazybones!”

Frisk flinched as a few drops of sweat dripped onto his forehead from Asriel's fur. “'Sup.”

“You really gotta start runnin' with me, Frisk! It feels great!” Asriel beamed, loudly drawing his lungs full of air, head peering around as he surveyed the lake. He looked up just in time to miss seeing Frisk get flushed as a drop of sweat dripped onto the human's lips, making him shudder and sit up on the edge of the wooden pier. Asriel let all the air he had filled himself with out with a satisfied sigh, hands on his hips in a victorious pose, a big smile on his muzzle.

Frisk sat there, wiping Az' sweat off his face with his arm. “Eh, later, Azzy. I just wanna relax today. And tomorrow… And probably the rest of the week.” Frisk chuckled while slowly wagging his legs in the tepid water, spooking off the few fishes that had grown curious about them.

“Bah! When'd you get so lazy, Mr. Most-Determined-Being-Around?” Asriel huffed, planting a hand on top of Frisk's head and ruffing up his hair to tease him, the human groaning and leaning away to get out of his pesky brother's reach.

“I dunno. Maybe defeating the God of Absolute Hyperdeath earned me a vacation for the rest of my life?” Frisk retorted, looking up at Az with a smug grin before edging closer to the pier's end as Asriel tried to ruffle up his hair again. “That was almost as easy to dodge as those, what were they called... Chaos Sabers?” He continued with the teasing, Asriel getting a bit flustered. Frisk could always get a rise out of him by reminding him of what an absolute nerd Asriel had been, even when he had the power of a god. Before Asriel could grab Frisk, the human slipped off the pier and into the water, clothes still on, swimming a couple feet away.

Frisk kept his head above the surface, still grinning smugly, turning around in the water so that he was facing the pier. The goat had an unamused, blushing slightly, standing at the end of the pier with his arms folded over his chest. “I was like, 8, okay?” He said defensively, getting adorably awkward whenever Frisk brought up that particular encounter. Sure, it had been emotional for all parties involved, but seriously. Shocker Breaker? And a 'battle robe' which totally wasn't a dress? ...Mascara?

Frisk didn't even need to say it. His coy, teasing grin told everything about his thoughts to Asriel, who rolled his eyes, looking to the side perhaps a bit bashfully.

Just to finish him off, and as revenge for getting his hair all messed up and icky with goat sweat, Frisk splashed water all over Asriel's front. It actually caught the boss monster off-guard, Asriel jumping back with a surprised bleat. Much to Frisk's delight, Asriel stumbled and lost his balance in the process, falling butt-first on the pier and then flopping into the water with an undignified splash, making Frisk burst into laughter.

“Baah! You, you, insolent human!” Asriel shouted as he thrashed about, his fluffy fur having a nasty habit of getting really heavy when it soaked up water. “You'll pay for this!” He bleated out, finally managing to grab a hold of the pier, hauling himself up on it, looking pissed. He stared daggers at Frisk, whom was still laughing so hard that it was hard to focus on keeping his head above the water, the goat's fuzzy fur dark and heavy with water. It'd take an hour or more for him to dry off with just a towel.

Frisk had to submerge half of his face underwater to keep Asriel from hearing the rest of his schadenfreude, the human slowly swimming further from the pier as Asriel made a half-hearted attempt at conjuring a magical star to throw at him. He seemed to realize that the big, cartoon-y star floating over his horned head wasn't helping him look like he was serious, the drenched goat flushing bright red before storming off to dry off, the star exploding into a short-lived rainbow.

***

Frisk finished setting fire to the sauna's stove, a half dozen burned matches littering the floor. It would have been so much easier if Az had been there to ignite the wood with his magic, but the sensitive guy had let Frisk's teasing get under his skin. Frisk felt bad about it, but couldn't exactly remedy the situation since Asriel had disappeared. Maybe he was out jogging again, or he could be using his magic to stay hidden and sulk. Frisk tried not to worry too much. He'd give his brother a big ol' hug and some make up cuddles as an apology. Maybe even boop his snoot. That’ll do the trick.

Frisk closed the cast iron hatch and sat up, dusting his knees off before heading out of the sauna. He had some time to kill before it got up to the right heat. The setting sun was casting orange light through the gaps between the trees on the horizon, and darkness steadily settling into the forest. The automatic lights around the lot were starting to flicker to life, keeping all the important paths illuminated.

Frisk smiled, enjoying the colourful sunset as he stood on the sauna's porch. The birdsong was still strong, as was the sound of crickets; nature was still very much awake, even as the sun was going down. He could hear the occasional splash of a fish catching something to eat from the lake’s surface.

And then he noticed Asriel. He was standing at the end of the pier, looking at the lake. Appearing rather… Ominous. Without hesitation, Frisk set off to meet him there, yearning to give his brother a hug after all the teasing.

As Frisk stepped on the pier's first floorboard he noticed that something was off about Asriel. He didn’t bob with the movement of the pier. Actually, he was floating a few inches off the wood, small amounts of light reflecting off his toe claws and pawpads. Additionally, now that Frisk was close enough to make him out properly in the dying light, he wasn't wearing anything, his body fully bared. Frisk tried not to stare.

When Frisk managed to look away from his cute butt, he noticed the tattoo-like streaks going around his furry form. Oh, shit. Maybe should have tried a little harder to find Asriel before he got all weird about things.

Frisk stumbled slightly, catching one foot on the wooden planks. He glanced down, and when he looked back up, Asriel had moved.. Facing Frisk now, he had a creepy, leering grin on his face, the sclera of his eyes pitch black, his irises were white slits that seemed to glow in the darkness.

Frisk tried not to panic, faltering to a stop on the pier. Sweat beaded on his forehead as the God of Hyperdeath stared at him, totally motionless.. The human tried his hardest not to let his gaze wander down his brother's fuzzy form, attempting to ignore the thought about how plump his sheath and nuts looked.

“C-come on Az, we can still hug this out.” Frisk began, taking a careful step back. “We talked about this, you can’t go Hyperdeath every time you get hurt feelings, it’s not healthy or constructive. I’m sorry for teasing you, okay? ...You’re not scaring me, so stop trying.”

Asriel didn’t move a muscle, he was unnaturally still. He looked… Hungry. Frisk considered the nature of the cabin, how far it was from anyone who might hear Frisk calling for help or, more likely, groaning lewdly. No one to help, no one to interrupt. Asriel could spend the next week like this without anyone to stop him.

An entire week. Suddenly, the decision to come and hang out here with Asriel all on his own seemed foolish. Frisk gulped, taking another step back and looking down quickly to make sure he didn’t misstep. When he looked back up, Asriel was closer. Frisk couldn’t help but flinch in shock, gasping quietly. Asriel’s mouth was open now, and he was panting lightly, his long tongue hanging lewdly from the corner of his mouth. Frisk couldn’t tell if he was angry or horny. Maybe both.

 

“...Oh fuck me.” Frisk muttered to himself with his heart in his throat, stepping off of the wood and onto the sand of the lakeside. Behind Asriel, the last of the orange light was rapidly dwindling, casting him in a demonic light. He was actually terrifying like this.

“I intend to, brother.” He heard Asriel mumble right back, the slits of his eyes glowing bright as the rest of his face was obscured by shadow. In the growing darkness, it was impossible to tell if he was still motionless, or slowly floating closer. 

Nope. Nuh uh. Nnnnnope. Not happening. Frisk had seen this particular horror movie before and he had no intention of getting killed. Well, not killed, but if this was anything like the other times Asriel had changed, he was packing 10 inches of demonic goat cock and was looking for a nice place to store it, and Frisk very much intended to be able to walk for the rest of the week. Frisk turned and ran for it, deciding that it was no longer worth trying to look fearless in the face of Asriel’s demonic countenance.

Frisk could have sworn he could feel Asriel's breath against his neck as he ran for the cabin, fumbling with the latch and then slamming the door shut, looking up from the latch and jumping at how close Asriel was to the glass on the other side. That horny, depraved grin didn't falter at all, even as Frisk locked the door, sweat rolling down his forehead from the brief dash and the awkward implications of how Asriel intended to exact revenge for the earlier teasing.

“C-c'mon Az, de-Hyperdeath yourself and let's hug it out, bro!” Frisk shouted through the front door's window, Asriel creepily floating away from the door without breaking eye contact or blinking. Some kind of a magical aura was dimming all the lights in his vicinity, meaning that Frisk couldn't get a proper look at his nude form as it hovered there like some friggin' alien. “I'll give you a nice back rub in the sauna! We can talk about stuff like adults! That's a much better option than me leaving you locked outside all night, right?”

Asriel’s eyes widened and he grinned even wider, looking up and gradually floating towards the second floor and the Oh Fuck the upstairs balcony was wide open.

Frisk dashed for the stairs, tripping on them a couple of times as he tried to clamber to the top. In two leaps flat, he made it to the balcony door, slamming it shut with a loud click. The human was panting, terror sweat rolling down his body, eyes darting wildly as he tried to see Asriel in the darkness. Maybe he got to the door in ti-

Frisk felt a hot breath waft over his neck.

“You're so slow, brother. You really should come running with me.” Asriel rumbled, Frisk frozen solid, one hand still on the door's knob. Frisk could feel lust dripping from his brother's voice.

A second later Frisk found out that Asriel's voice had literally been dripping, feeling splatters of hot drool land on his exposed neck and upper back. Frisk only had shorts on after the swim in the lake, having left his wet shirt drying on the clothes line next the sauna.

The human didn't move a muscle. He was frantically racking his brain for a plan that would save him from Asriel’s looming revenge, which he suspected would take the form of a savage fucking. Since Asriel had grown up, his edgy demonic persona had come to be synonymous with Frisk being unable to walk properly for days at a time, if he was lucky enough to not get injured outright by his brother’s insatiable lust.

“Asriel...” Frisk started, trying to sound calm and in control. His follow up died in his throat, coming out as a surprised gasp instead as he felt a hot, slimey tongue trail up along his spine, starting at the small of his back and gradually sliding up between his shoulderblades to his neck. Behind the wet appendage, Frisk could feel a thick, warm trail of drool in its wake. It made his skin tingle.

“Az! What are-” He tried again, only to feel Asriel's hands grab him and spin him around, pinning him against the door. Before he could react, the demon goat forced Frisk into a kiss, the human's cheeks flushing red. Those clawed fingers were clenching his shoulders, keeping him pinned as he was smooched by his caprine brother. Frisk knew what would happen if he parted his lips even a little bit, the slender human squirming against the door and trying his hardest to keep Asriel from getting what he wanted, hands pushing against his fuzzy chest, trying to fend him off...

But, like always, Frisk's defenses failed, a thick and broad tongue worming its way into his mouth, forcing his jaws open, the flushed male squirming and groaning as his mouth and throat wereviolated. Az was doing something new this time, deepening Frisk's panic – that tongue and the excessive drool oozing from it tasted like liquorice, a taste which Frisk didn't particularly like.

Just as that invasive tongue was trying to slide down his throat, Frisk managed to overpower Asriel with a burst of Determination, giving the tattooed goat's chest a harsh shove to send him reeling back. While the God of Hyperdeath tried to regain his footing, Frisk yanked the balcony door open and ran through it, hopping over the railing and managing to pull of an expert roll to soften the blow as he fell down on the ground. As he ran for the sauna in the near darkness, he could hear Asriel laugh like a madman. If Frisk hadn't felt so hot and bothered by his brother's forceful advances, he'd been outright terrified.

In seconds flat, Frisk had cleared the distance between the main cabin and the sauna, nearly tripping over as his toes bumped against the door's threshold, slamming it shut. Thankfully the sauna had a lock in its door, which Frisk promptly used before moving from the waiting room to the sauna itself.

His heart was pounding and his eyes were wide from adrenaline as he sat down on the middle pew. It took him a moment to realize that his mouth still tasted like pungent liquorice, making him spit and groan as he tried to clear the taste out. As it turned out, all that thick drool Asriel had left in and on him was black and tar-like, the thought and feeling of that gunk slowly oozing down his throat making Frisk shudder hard.

He hunched over as he hacked up thick, slimy strands of the black drool, the heat from the sauna making him even sweatier. Instinctively, he wriggled out of his shorts and underwear, kicking them on the floor, mumbling a “Shit!” to himself as he realized he'd just thrown them into a puddle of black goo that he'd been spitting out. He kept hocking up black slime, the gunk flying out in messy and goopy arcs, splattering loudly on the floor. Frisk groaned in disgust as a few streaks of the stuff landed on his thighs, leaving black stains on his skin even as he wiped and washed the tarry stuff off. This stuff was seriously nasty, ugh.

Well, at least he didn't hear Asriel anywhere nearby. There was only one entrance to the sauna building and Frisk had locked that. For now, he was safe, unless Asriel got horny enough to actually bust through the door.

***

Frisk was feeling woozy. He hoped it was because of the hot sauna, but he had a creeping suspicion that it was because of the black goo his brother had drooled onto his back and mouth and throat. Even though he had wiped and spat it all out, it had left the skin and flesh it had touched black. From what Frisk could see, his back now had a weird-looking tattoo going down along his spine, a few streaks of black on his legs, his tongue and throat just as jet black.

It was like he was running a fever. Frisk groaned, holding his head with both hands, shivering. Worse yet, he could feel a taunting, tantalizing tingling in his groin, aching to be touched, his shaft half-hard from the exotic sensation alone. Goddamn Asriel and his lewd magics, why couldn't he use his time to learn something productive instead?

Productive… The word invoked intimate, lewd memories of Asriel's privates in Frisk's mind. The human groaned and smacked his forehead with both palms a few times in the hopes that would clear the vile thoughts out.

It was getting harder to think straight. Flashbacks from the numerous times Asriel had assumed his demonic form and done depraved things to Frisk were constantly interrupting his train of thought. Unwanted arousal was building in him, his half-hard manhood was twitching and dripping with pre, the memory of his brother's tongue wriggling in his mouth still so fresh…

That's it. Frisk had to rub one off to stave off the lewd, kinky thoughts that were trying to erode his mental barriers. With a determined huff, he wrapped one hand's fingers around his shaft, stroking it intently, helping it to grow fully erect in a matter seconds. Then Frisk started to beat himself off, groaning, resting his back against the upper pew, soft slaps and smacks filling the hot and humid air as his hand pumped his manhood.

At first, Frisk tried to focus on the fairly normal, fairly vanilla stuff he usually looked at on the Internet whenever he wanted to relieve some tension. To his chagrin, none of it seemed to work. It was rapidly becoming very clear that Asriel's foul magic was affecting his thoughts to a disturbing degree. In stark contrast, thinking about all the things his brother had done to him over the years was making his member pulse and throb harder than ever, Frisk panting and moaning as his thoughts focused on memories involving the demonic goat claiming him as all his own.

Once Frisk started down that mental road, those memories and fantasies echoing in his mind, it only took a few more seconds for him to reach his peak. With a wavering, lewd moan he started to cum, fingers trembling as they gripped his angrily pulsing dick, wads of spunk arcing through the air and noisily splattering on the sauna's door. It was a surprisingly heavy orgasm, too, a solid eight jets of white, cloudy spunk shooting out before it turned into a slow drool.

The very pleasant climax left Frisk panting, hot shivers running through his smooth-skinned body, his tongue sticking out a little as he sat there and panted for breath on the wooden pew. Rivulets of sweat were trailing down his silky skin, his dick turning semi-soft again now that it was done spewing out his load, his toes curling up from the afterglow. God, that was amazing.

Frisk heard the building's door unlock and then open. He could hear Asriel stepping into the waiting room.

“Urah ha ha… Don’t think I didn’t hear those sick, twisted fantasies of me, dear brother.” The demonic goat spoke through the sauna's door, sounding like he was leaning his back against it. Frisk was now trapped in the hot room. His skin was flushed red with embarrasment at being caught, hislegs instinctively closing up to hide his nethers even though every word spoken with that alluring, handsome voice was making his flaccid shaft twitch. Frisk could feel Asriel rifling through his thoughts with some kind of magic.

Shit. How much had he seen? Just now? Before? Oh god, before.. Hide the memory, of before, of how hot it was when his sweat had dripped onto his lip, hideithideithideit-

“…Brother! That's lewd, even by my standards. You want to taste my sweat? Or, ‘musk’, as you seem to refer to it.”

-hideithideithideithide-

“...Lick my sweaty feet? Oh my…” Asriel chuckled, and Frisk his his face in his hands, burning with embarrassment. “What do you think mum and dad would say if they knew their adopted son was such a little pervert? Still, I suppose I can indulge your odd kinks, my dear brother, but only if you submit to me fully. And you know what that means, right?”

Oh, no. Not this again. Frisk refused to wear a collar around his neck, no matter what Asriel tried. Asriel had been chasing this kind of submission in his lewd Hyperdeath pursuits for years. Frisk was determined to never give into that temptation. Wait, temptation?

“Yesss, brother, submit to me! I will fulfill your every twisted fantasy!” The demonic caprine urged, Frisk hearing him turn around and trace his claws along the sauna's door, no doubt leaving suspicious scratch marks on it.

Frisk channeled some of his innate stubbornness to clear his thoughts, shaking off visions of dropping onto all fours and groveling as his brother's feet. He staggered upright and reached an arm out, grabbing the door's handle and pulling on it hard to make sure it remained keep it tightly closed. Frisk squeezed the handle so hard he felt his claws prick against his-

...His claws?

The human's eyes widened from shock. His fingernails had turned into stubby obsidian claws that were nicking the skin of his palm as he held the handle. As his eyes trailed further up his arm, he saw his small amount of body hair had turned into something that looked like white fur.

Frisk looked his body over. Tufts of creamy, fluffy fur were here and there, his toenails having turned into black claws, his tongue feeling over his elongated canines. His free hand felt over his head, feeling two hard nubs amidst his hair, near his forehead.

“Do you like it? I always wanted a fluffy, fuzzy brother to hug, cuddle and bleat with. And, of course, keep. You could be my pet, Frisk.”

This was worse than the times when Asriel had changed Frisk's gender. His brain signaled for his vocal chords to produce a shocked scream, but all that came out was a surprised bleat.

“Baah-sriel! Wh-what did you do?!” Frisk bleated out in horror, watching as the tufts of fur were spreading to cover more of his skin, his panting becoming frantic from both the unusual sensation of his body changing, and the instinctual terror of watching his body shift. The sauna felt noticeably hotter the more furry Frisk became.

“You’d like that, wouldn’t you Frisk? Being mine would make you the black sheep of the Dreemurr herd, but...” Asriel tried to open the door, tugging on it hard, but Frisk was holding on tight. “...You'd be MY black sheep.”

“Az! Th-this is too far! You’ve had your fun, now change me back!” Frisk shouted, gripping tufts of his white fur in the hopes that would stop it from spreading. His face was contorting into a snout, tears beading in the corners of his eyes. This was way, way messed up.

Frisk noticed that the fur sprouting from the black marks Asriel's weird goo had left was jet black. It looked a lot like the 'tattoos' Asriel had in his Hyperdeath form.

Asriel tried the door again, this time a lot harder. Frisk had to clutch the handle with both hands, propping up a leg against the wall to add power to his pull.

“Let me in, Frisk. Accept my power over you. If you do, I’ll give you what you want. I'll let you worship my feet.”

Asriel's magic had rewired Frisk's brain in all the wrong ways. The mental image of pressing his face against his brother's padded paws made Frisk go from half-mast to full, causing him to shudder. His cheeks were blazing like hot coals under all the velvety fur that was spreading onto them. A new attempt at yanking the sauna's door open snapped Frisk out of the fantasy, grunting as he fought to keep the door shut. The two screws the handle was attached to the door with had come up a little, the two young adults using an excessive amount of force in their tug-of-war.

“Once you do, maybe if you behave like a good little goat and bleat for me, I'll let you have your humanity back tomorrow.” Asriel continued with his teasing, another quirk of his twisted magic revealing itself to Frisk as he had to clamp his mouth shut to suppress the urge to bleat.

“Ff- Baah off, Az!” Frisk shouted, his shock and lust starting to get replaced with anger. He hated the erotic tingle that went down his back when he'd baa'd for his brother, and he tried to focus on that hate as a rallying point. The heat in the sauna was getting nauseating, seeing his face elongate into a muzzle was damn near nightmarish, and he could feel his curved horns scrape against the upper pew as he fought to keep the door shut.

Wait. How big were his horns?

Frisk briefly pulled one hand away from the door to feel over his brand new horns. They were pretty long and curved, a quick glance at the reflection in the bucket of water confirming that they looked big and menacing.

Frisk got an idea, a coy smirk on his muzzle.

Just as Asriel yanked on the door again, Frisk let go, sending the God of Absolute Hyperdeath stumbling back from the momentum. Asriel nearly stumbled all the way against the wall, stopping but a few inches from it, black eyes wide from surprise.

And then Frisk finished him off with a massive headbutt right against Asriel's chest, ramming him against the wall with a loud thunk, wood creaking and snapping in places. Frisk noticed that his brother had done a bang-up job in turning him into a goat, he barely felt it as he slammed his horned head against the now gasping and grunting demonic male.

“Turn me baah-ck, you dick!” Frisk shouted, keeping Asriel pinned against the wall, the top of his horned head flat against his chest, the black-furred goat huffing and grunting. Frisk was completely prepared to crack a few of Az' ribs to get his humanity back.

Asriel was winded, wheezing for air, chest struggling to heave under Frisk's crushing headbutt. Frisk had a big, victorious grin on his face. He actually had the upper hand, for the first time in years. Then again, he rarely was this motivated to put an end to Asriel's lewd shenanigans.

The wheezing breaths stopped. Frisk blinked, slightly alarmed about that, about to step back to give his brother some breathing space…

...Only to feel Asriel's hands grab him by his horns. Pulling on them instead of pushing, keeping Frisk against his chest.

“Did you really think your God could fall to a mere headbutt?” Asriel's amused voice was seething with lust. He began to pull Frisk down along his chest and belly, hands gripping those horns with unnatural strength, Frisk panicking and huffing as his muzzle was forced lower and lower. Towards a very clear destination.

Frisk tried his hardest to pull away from Asriel, bleating as he couldn't budge an inch, his brother's demonic form far too strong physically. Which meant that he had been toying with Frisk with the whole tug-of-war ordeal with the sauna's door.

“Feisty. That attitude will serve you well in your next life as my property, brother.”

A heady, musky scent was wafting into Frisk's nose as his snout was pushed closer to that furry sheath. The intense smell made his nostrils flare, maw watering, the former human bleating and struggling with all his might to break free of Asriel's hold. Frisk had been so very wrong about his horns – they were big because the demonic goat wanted handles to grab, not as an oversight on Asriel's part. And there was no way goat monsters had a sense of smell this good, Frisk's eyes fluttering as that masculine scent became stronger and stronger as his snout slid lower along Asriel's belly.

Asriel chuckled, a sadistic smirk on his face as he forced Frisk's head down until it was on level with his groin, the former human dropping onto his knees. Frisk's breathing was haphazard at best, as if he was switching between trying to hold his breath and huffing in more of that musky smell, the demonic goat keeping Frisk's snout pressed against his pubic fur. He pushed on Frisk's horns, angling his new caprine brother so that his lips pressed into the slightly coarse fur.

“Breath it in, brother… Don't fight it.” The tattooed goat talked with a soft, yet authoritative, voice that made Frisk gasp and obey, it feeling alarmingly instinctual. That manly musk was making Frisk's maw water, his lower jaw growing slack, eyes fluttering as he kept sniffing his brother's crotch fur, the tip of his snout in the small gap between Asriel's thick sheath and heavy sac. His musk was all that he could smell, every breath he took laden with the potent aroma, making it harder and harder to think. Like enjoying sip after sip of expensive, delicious wine.

Frisk groaned, shivering as arousal welled up in him from the sheer smell of his brother's groin, the former human's shaft already rock hard again. It felt like he was buzzed, his belly growling as Frisk got the munchies like he always did when drinking on an empty stomach… Except this time, it was a different kind of hunger, his vacant-looking eyes going crosseyed as they focused on that plump sheath resting atop of his snout. The tip of his brother's member poking out teasingly, causing Frisk to groan with lust, his hot breath washing over Asriel's groin, making that alluring sight twitch.

As if he was in a trance, Frisk opened his maw, tongue pushing out and pressing against all that musky fur, slowly dragging it up and over the sheath's opening. Frisk shuddered from the intense, addictively delicious taste, his toes curling and eyes rolling back, a shiver of delight going across his changed form as he heard his brother moan from the lick. Lust-drunk and eager to hear Asriel's moans, Frisk laid his hands on the taller goat's hips, gripping tufts of fur as he began to trail his long, broad tongue all over the demonic caprine's groin, trembling as it was getting impossible to think straight. He lost himself in licking over that plump sheath, dipping lower to slather his brother's orbs, the warped human groaning and panting as he indulged his darkest desires. As Az' shaft began to emerge his tongue dragged along the underside of it, feeling it throb heavily against his tongue, only urging him keep worshiping his brother. Soon that large, 10-inch dick was resting over the top of Frisk's muzzle, the fleshy spear of meat all that the former human could see, fantasies of that beast plunging deep into him making him shudder and whimper in need.

Frisk passionately kissed the gap between Asriel's sheath and nuts before pulling his head back, eager to wrap his lips around that fat cock. His fingers clenched Asriel's fur harder as his lips got closer and closer to that thick tip, watching pre drip from his shaft onto Frisk's muzzle with unfaltering attention, the sight of the hard and twitching shaft making his stubby tail hike up. Frisk couldn't help but to pull his head back an inch to properly adore that large manhood, primal hunger in his eyes, maw open as he panted lustfully.

Then a stark realization cleared up his lust-addled mind. He didn't feel Asriel's hands holding his horns. As his eyes wandered up to look at Asriel's smug grin, Frisk reckoned that he hadn't been forcibly held against that musky crotch for a long, long while.

With the newly found clarity from the shocking realization, Frisk tried to crawl and run away from his demonic-looking brother, only to have his horns grabbed again. Asriel had was using magic to gain unnatural strength in his muscles, Frisk not able to move at all when his horns were grabbed, no matter how hard he tried. As if his horns had been cast into a block of concrete.

“Ah, 'determination'.” Asriel rumbled, a stern look on his face as he stared down at Frisk. The changed human looked like a deer in headlights, eyes darting, body squirming as he tried to get away from Asriel. It looked rather silly, his head unmoving in the God of Hyperdeath's grip. “You really need to learn how to put it to good use, my beloved brother.”

Asriel maneuvered Frisk's head again, forcing the first two inches of his shaft into Frisk's maw. Try as he might, the transformed human couldn't bite down, his lower jaw lacking the strength to achieve more than seal his lips around his brother's manhood. Frisk even tried punching and clawing at Asriel, but his muscles felt weak and fatigued, his fists unable to do more than bop and pat his evil-looking brother. The only muscle that seemed to be working fully under his command was his tongue, which was desperately trying to recoil and stay off from that musky, pulsing cocktip in his maw.

Asriel pulled on Frisk's curved, grooved horns, forcing more and more of that throbbing member into Frisk's mouth. Frisk groaned and trembled, still trying to fight and pry himself free. His caprine brother's magics had rooted deep into him, and no matter how much determination the former human had, he couldn't reverse or even stall the corruption taking place. That, and… Frisk really, really loved the taste of Asriel's musk on his tongue, the elongated appendage pressing against that pulsing pillar of meat, curling around it, the trickle of precum that Frisk's efforts were rewarded with making his eyes flutter and his own loins tense up as its salty taste spread around his maw.

Frisk's entire neck tensed as Asriel's cocktip nudged against his throat, the changed human gagging some as the thick tip touched the back of his throat a second later. A rough buck of Asriel's hips forced the first inches of that pulsing shaft down Frisk's throat, making it bulge lewdly. Another thrust forced Frisk's lips against Asriel's crotch, the gagged male huffing and groaning as every breath he took made his nose and lungs tingle from that potent musk, maw salivating and weakly clenching around that huge cock.

Frisk's struggling faded as he was forced to take in that enthralling scent and taste. His fingers and toes twitched and curled at random, eyes becoming half-lidded, the dissatisfied groans turning into muffled moans. He was getting a high from sniffing his brother's crotchfur and lazily sucking on his dick.

Before Frisk fully fell into a trance, Asriel pulled his hips back, sliding half of his shaft out and then gently easing it back in. He did it a few times, Frisk shuddering as that hot, musky pillar of meat rubbed against his broad tongue, the tip slipping down his throat with each pass earning a gag or a gurgle from Frisk.

And then, as if a switch had been flicked, Asriel started facefucking Frisk raw. Using Frisk's horns like handles, he slid his maw up and down along that huge and throbbing shaft, forcing as much of it down his throat as he could. His thrusts were short but hard, most of the work done by yanking Frisk's head down until the snout bumped against his crotch and his dick bulged his throat obscenely, the fleshy passage convulsing wildly. Frisk's gag reflex was still as strong as ever, signaling the powerful muscles of his throat to contract and clamp down around the invading manhood, which was exactly what Asriel was looking for. The demonic goat groaned and trembled in ecstasy as he savagely used his formerly human brother's mouth and throat for his own pleasure, disregarding the distressed gurgling sounds and spastic squirms Frisk was doing.

Frisk struggled with whatever little strength he had left, fingers twitching as they gripped tufts of fur on Asriel's sides to pull on, legs kicking along the floor at random as he tried to get up. He wheezed for air whenever his brother's dick slipped out of his throat, able to get just enough to survive on before getting stuffed again, the burning instinct to breathe only making the muscles in his throat tighten harder. His sight was getting blurry, head woozy from both the intoxicating musk and slight asphyxiation, teetering on the edge of consciousness.

And on some twisted level, Frisk was loving it. Even though his body protested with all its fading might, he wanted more. Everything about it was so wrong that it felt right, his dimmed consciousness still picking up the sensations from his own rock-hard dick throbbing and spurting pre even though he was getting battered.

Asriel's thrusts got erratic as he neared his climax, his long manhood throbbing violently as it violated Frisk's throat with each thrust, Frisk's body rocked by harsh spasms as his breathing reflex fought to keep his lungs full of fresh air. Asriel hunched over some, grunting and groaning like a feral beast as he rutted his brother's maw.

After a few solid minutes of brutally abusing Frisk's head Asriel finally crossed over his limit, letting out a mighty bleat as he jammed his cock deep down his stunned brother's throat, the heavy shaft lurching powerfully as waves of thick cum blasted out. The viscous spunk was coming out in such volume that Frisk's belly was filled in the span of a few throbs, his abdomen rounding out some as he was packed full off the creamy seed. Asriel's orgasm lasted fantastically long, leaving Frisk full to the point that a good deal of cum sloshed around in his esophagus, stomach not able to contain it all.

Asriel's hips bucked a couple more times before he gave Frisk's horns a hard shove, sending the changed human onto his back on the floor. Frisk was still stunned from burning, all-encompassing lust, throat convulsing as it tried to reflexively suck down the last of his brother's divine essence down into his pudgy gullet, his own manhood sputtering pre onto his furry belly. The angrily throbbing shaft hadn't been touched once throughout the whole ordeal, Frisk on the edge of a climax from simply getting facefucked by his brother.

Even though Asriel had just cummed hard enough to put a stallion to shame, the edgy goat monster was far from done. With a devious chuckled, he moved into the sauna itself, grabbing one of Frisk's horns while walking, dragging his dazzled goat-brother into the swelteringly hot room.

The Monster Prince dropped Frisk's head on the lowest of the three wooden pews, himself climbing on the top one, sitting down comfortably and rumbling in the pleasant, if harsh, heat. His delicate skin hidden under all that white fur started to sweat profusely, matting his fur some. Frisk was low enough to be spared from the effects of the heat, some intelligence clearly returning to his eyes as he lay there, body sprawled on the floor, head propped up on the bottom pew. Excess cum was drooling from between his lips, a few inches of tongue sticking out in front of his muzzle.

It took a couple minutes for Frisk's determination to clear out the lusty and hazy thoughts, the trembling male trying to get up on shaky limbs and coughing up a few mouthfuls of spunk. His attempts to escape continued right up until Asriel lifted one footpaw up, holding it a few inches away from Frisk's face, presenting the padded paw to the magic-wracked human. “Worship.”

Frisk cocked his head in confusion, eyes half-lidded, some internal turbulence clearly going on in the former human's head. On one side, his determination was screaming at him to get up and run to recollect his thoughts and formulate a plan, while on the other side he just wanted pleasure his brother-lover-god-whatever Asriel in any way, shape or form he could. The command, 'worship', had been very clear in itself, though.

“Worship my foot and I will give you back your humanity, my brother.”

Even though that should have been more than enough to tip the scales, Frisk hesitated, that innate, eternal determination clearing up his mind more and more now that his face wasn't buried in musky crotch fluff. His nose could pick up the enticing, exhilarating scent coming from that presented paw, glistening with sweat, making Frisk groan and shake his head in denial of the simple fact that every breath carrying even the smallest trace of that musky smell made his achingly hard dick twitch and dribble pre.

“Th-this… Too m-much...” Frisk mumbled with a slackened jaw, desperately trying to pry his eyes away from that padded paw, placing a hand over his snout in a vain attempt at keeping that musk from affecting him. It took him considerable effort to clamber onto his knees, Asriel moving his presented footpaw in sync with Frisk's muzzle, always keeping it a few mere inches away from the nearly enthralled former human. As Frisk felt his thoughts get increasingly depraved and as the urge to submit to his brother grew harder to ignore, he even thought about cheating his way out and LOADing to last night to spare himself – but the further he tried to find the familiar path to activating the time-warping event, the more the knowledge on how to do it slipped from Frisk. Demon Asriel appeared to be very, very determined in having his way with Frisk tonight.

“Worship me, pet.”

Those words elicited a desperate moan from Frisk, his fur-covered body shuddering heavily as the last cables keeping his inhibitions in check snapped one by one, the hand dropping from his snout as the white-and-black nuzzled luxuriously against Asriel's sole. Right away, Frisk dragged the top of his muzzle up along that padded foot, groaning in twisted delight as he felt those warm and firm pads brush against his fur, the larger male's sweat seeping into Frisk's fluff.

“Good boy.” Demon Asriel praised Frisk as he pressed his snout right under those clawed toes, the changed human's eyes fluttering as he nuzzled into that divine paw. Frisk dragged his tongue all the way from the heel to the obsidian pads, the overpowering, addictive taste making his hips buck and twitch, one hand reaching down to grasp his shockingly hard manhood, the warped human moaning against that large paw as he jacked himself off to how good it felt to have it press against his face.

Frisk really did look like an addict getting his fix, nuzzling and slathering at Asriel's foot as if his life depended on it, meticulously making sure that every part of his muzzle and head had been stained by his brother's corruptive sweat. All Asriel needed to do was lightly press his paw against his slutty brother's affections, grinning slyly, a malicious glint in his black eyes as he watched the human he had twisted into a goat monster lose himself. Better yet, Frisk wasn't getting any release from the raging fires of lust consuming his mind, both hands furiously beating his still human-like shaft, messy threads of pre constantly shooting out and noisily splattering onto the sauna's floor and pews. But no matter how hard and fast tried to get himself to cum, he couldn't, held on the verge of an orgasm, cock so sensitive and overexcited that a single stroke from a feather was all that was needed to send Frisk over his peak – but it had to be done by someone other than himself, another part of Asriel's 'curse'.

“B-baahng! I-I can't c-cum, Azzy!” Frisk cried out, his shaky, pre-covered hands slowly withdrawing from his angrily pulsing shaft, more pre squirting out than what Frisk normally cummed regularly as a human. Frisk felt over his swollen, overgrown nuts with a slimy hand, shuddering at how heavy the two taut orbs felt, his other hand reaching to grope his own rump, a claw subconsciously reaching to prick his clenched anus, making him bleat in shock. The puckered skin felt extremely sensitive, Frisk feeling muscles inside his hips contract and tense powerful, his back arching, head pulling away from that drool-coated footpaw.

Asriel chuckled sadistically, pressing the now-unattended foot back against Frisk's muzzle, the other footpaw following suit a second later. Frisk froze in place as his head was mushed between both of his brother's feet, soles pressing against his cheeks, toes groping the sides of his head. Thanks to the foot fetish that Frisk had, which had been amplified considerably by Asriel's corrupting magic, his brain was frying from all the information it tried to process. Frisk's body locked up as his mind was overwhelmed with the fact that he now had both of his divine brother's feet rubbing and pressing against his horned head, his mouth wide open and drooling, eyes looking more vacant by the second. Feet, feet, feet…

Even after Asriel moved his feet away from Frisk, he remained paralyzed, little more than a passenger in his own body. For the moment, all resistance was gone from the former human, which became very evident as Asriel grabbed him by his horns again, lifting Frisk’s limp body up while he himself stepped down from the wooden pews, moving behind Frisk. He positioned Frisk into the pews, elbows on the middle pew and head resting on the top one. Frisk's mind was still struggling to recover from the feedback loop of sensations Asriel had inflicted upon him, his new stubby and fluffy tail twitching cutely. He felt Asriel's hands grab his rump, groping and kneading those plump cheeks, the feeling and thought of his brother adoring and lusting over his body making Frisk's rock-hard shaft surge even more clear, slimy pre-fluids all over the wooden pews and the stone floor.

“Aah… B-baah...” Frisk groaned, slowly regaining some control over his body, enough to turn his head as it lay on the top pew. He managed to get one eye focused on Asriel, watching as the demonic goat lusted over Frisk's slender form, a hand feeling over his furry back, the claws gently raking the skin hidden underneath all the ivory white fur. The parts of Frisk's skin covered by the black streaks of fur felt particularly sensitive, making him shiver and arch his back, Asriel's fingertips rifling through the slate fur making the former human weak in the knees. “Baah-sriel…”

“Rrh, isn't it delicious? I can feel your determination flickering somewhere deep in there, even after all I've done to break your spirit.” Asriel spoke as he dipped a hand under Frisk, trailing his fingers across the changed human's pecs, sliding his claws down over to his still swollen belly. “Fighting against impossible odds, staying lit even under a sea of my most potent, defiling magics.”

“You really are something special.” He continued, hands sliding to grab Frisk's hip and side, the taller goat slowly leaning over his defiled brother. Frisk could feel Asriel's hot and hard member slide between his asscheeks, the pulsing manhood still slick from the facefuck earlier. The large shaft was constantly oozing pre, Asriel grinding the underside of that meaty dick across Frisk's rear entrance. “That's why I want you, Frisk. I enjoy the challenge, and from what I can see, you enjoy losing. I want you to be all mine.”

Frisk still was in no condition to respond, thoughts a bit more clearer but his body still sluggish and not responding. He was little more than a doll that Asriel was free to use as he wished.

“You in there, brother? You hear me? All...” Asriel whispered right into Frisk’s ear as he pressed the tip of his shaft against his anus, forcing it in with agonizing slowness. The tight ring of muscle squeezed harshly around Asriel's invading appendage, which only prompted the empowered monster to use more force in his grinding, easily overpowering Frisk's defenses. Frisk shuddered as he felt that hard cocktip pulse against his inner muscles, the sensation of pre squirting deep into him making his stubby tail hike up and stay like that.

“...Mine.” The demonic caprine finished, breaking into a sustained sinister chuckle as he slammed his hips forward, driving half of that gigantic, throbbing cock into Frisk in the span of a second. Frisk bleated loudly, his whole body tensing up as that monstrous shaft speared him. It was always like that when Asriel went Hyperdeath on Frisk – The perverted goat used magic to ensure that Frisk was virginally tight on the first attempt, both for the sake of his own carnal pleasure and for the purposes of sadistic delight, groaning with warped satisfaction as Frisk squirmed and quaked under him.

Frisk was gasping for air, fingers weakly clawing the wooden boards, tears beading at the corners of his eyes. It felt like his ass was splitting apart, and worse yet, his brain was getting some kind of sadistic pleasure from it, his rock-hard manhood jetting pre with ever more vigor. His legs tried to give in, but Asriel's strong hands kept Frisk up by his hips, the kinky demon's perverted delight at Frisk’s struggles echoing in his ears. Before Frisk could adjust to the girth, Asriel slid the rest of his huge shaft inside with a sickening squelch, forcing a masochistic bleat so loud from Frisk that a good deal of wildlife cleared out from the areas surrounding the cabin grounds.

Without pause, Asriel worked himself into a steady rhythm of pistoning into Frisk's ass. Lustful grunts and moans echoed off the sauna's walls as the two caprines mated, Frisk's thoughts dulling and slowing down as his head was battered by crashing waves of firstly, intense pain and then not long after, raw bliss, as his brother's massive cock rammed so deep inside of his tender body, harshly grinding against his prostate with each pass and forcing his insides wider with each thrust. That hefty and constantly throbbing dick pressed and rubbed against all the right spots to make Frisk's inner passages convulse and ripple around it, every powerful contraction making the changed human let out sharp gasp between his pleasured panting and bleating.

Asriel wasn't showing any signs of slowing down, or speeding up for that matter, rutting Frisk and taking his time in enjoying it. It was like the male covered with jagged black markings wasn't even seeking carnal pleasure for himself, instead enjoying seeing his brother squirm and lose himself to his lusts as his ass was ruined. Asriel leaned over Frisk, wafting his hot and humid breath against the former human's neck, focusing on the newly sensitive black marking and forcing deep shivers out of him. The demonic-looking male was able to suppress his own sounds of pleasure through a mix of sheer willpower and magic, meaning that all Frisk could hear was his own wanton cries of pleasure and the lewd sounds of Asriel's slick member sinking into Frisk's insides, over and over again.

Asriel kept going for several minutes longer, reducing his brother to a drooling, twitching mess before abruptly stopping. He left his 10-inch cock buried deep within Frisk, the rigid flesh pulsing hotly against the former human's much-abused prostate. But Asriel wasn't cumming, and neither was Frisk.

It took a few moments for Frisk's eternally burning determination to bring a spark of intellect back to his thoughts. The weak, constant bleating tapered off, the white-furred goat panting exhaustedly and shuddering under his brother, his hips weakly twitching as he tried to urge Asriel to continue. Instead, the demonic male just chuckled, resting on Frisk's back, head sliding right next to Frisk's, a black eye with a glowing white iris gazing deep into the former human’s own. Asriel's eyes had a sadistic glint, an equally perverted smirk on his muzzle. He wanted something, and even in Frisk’s addled state, he had a suspicion as to what it might be.

Frisk started to squirm weakly, blushing darkly under his cheekfur and trying to turn away from that piercing glare. He was so close to finally getting some release, trying to reach down to stroke his achingly hard dick, only for Asriel to grab his wrist to stop him. That made Frisk whimper, trying again with his free hand, Asriel snatching it and keeping it from ever laying a finger on his pre-sputtering shaft.

Frisk let out an agonized bleat, his balls aching from the sustained desire to cum. In desperation, he tried to clench his inner muscles to press Asriel's shaft harder against his oversensitive prostate, hoping that it would be enough to get him to orgasm. Frisk even went as far as pressing himself back against his dominant brother's crotch, wiggling his hips, whimpering again as he desperately wanted Asriel to keep fucking him raw, no matter how much he wanted to deny those desires.

“Beg for it.”

There it was, just as he had feared. Frisk's face looked like a red beacon, even through all that fluffy fur. It was like someone had emptied a barrel of embarrassment into the huge pool of depraved desires in Frisk's head. He wanted to cum so desperately that he would have given a finger or two for the privilege, but he wasn't ready to give up his pride. Pride that was struggling to justify its existence at this point, considering he had just been bleating like a sow in heat while his ass was being destroyed by his brother. That and the whole ordeal with shamelessly slathering his brother’s feet, just before he'd been just propped up and rutted. Oh, and how prior to the feet slathering, he had been huffing at his brother's crotch like junkie going through withdrawals. Still, pride.

Frisk squirmed harder, making Asriel chuckle in delight as he kept his former human brother pinned under him. Frisk kept trying to avoid Asriel's perverted gaze, but found it to be impossible in his current position, that lecherous stare only further undermining his self-confidence. He wasn't even sure if he was struggling and fidgeting to get free or to get his brother to continue ravage his tailhole.He was quickly reminded of the truth as Asriel teasingly bucked his hips, causing Frisk to gasp.

“F-fuck me.” Frisk mumbled, his bashful but desperately lustful look making Asriel's lascivious smirk turn into a gleeful grin. “Pl-please?” 

Asriel was silent and motionless. All he did was stare at Frisk with that perverted grin, clearly wanting Frisk to give in and put all his effort into it.

“Pl-please fuck me, Asriel.” Frisk pleaded, fidgeting under his caprine brother. He rarely made him jump through this many hoops during their lewd sessions, the evil-looking male really on a sadistic streak tonight. Frisk anxiously waited for a response, any response, but even Asriel's dick had stopped throbbing. It was still rock hard and infernally hot against his inner flesh, which was trying to make it twitch with desperate clenches and squeezes.

“Br-brother, please! F-fuck me raw!” Frisk cried out, blushing and shuddering at his own words, squirming and frantically trying to get Asriel to resume by grinding his butt up against his crotch, loose and battered muscles trying to entice his brother with feverish ripples and convulsions. “I w-want you to! I NEED you to!” He continued, any mental barriers that had repaired coming tumbling down again, a twisted kind of satisfaction filling the former human with warmth as he begged his brother to mate with him. “PLEASE FUCK ME, ASRIEL!”

“You are MINE.” Asriel snarled as he yanked his hips back, cock sliding all the way out of Frisk's tender hole before he slammed it back inside with enough force to lift Frisk in the air. Frisk's eyes went wide, pupils becoming small dots as Asriel pounded him harder than ever. It was outright violent, the demonic male slamming against Frisk with enough force to break any lesser man's pelvis, Frisk's voice breaking as he bleated in masochistic ecstasy. He felt Asriel grab him by his horns again, pulling on them as he had his way with Frisk's increasingly sore and numb ass. It was such an exotic, erotic brew of sensations, Frisk’s nerves constantly switching between signaling a soothing numbness and a perversely refreshing burning and zapping sensation, all the while accompanied by an undercurrent of raw surges of carnal pleasure as his abused prostate was mercilessly pulverised.

Frisk could feel the orgasm he so coveted building, everything in his waist region tensing up in that telltale fashion, his heavy orbs lifting up in preparation, his shaft looking like it was about to explode from pressure as the former human dribbled precum like a faucet. Frisk tried to move his hands so that he could finish himself off, but his motor control was shot to hell from Asriel's savage rutting. But Frisk was DETERMINED, one arm managing to flop down from the pew, dangling and twitching, it taking great amounts of effort to move it even an inch closer to his aching rod. He would jack off – Asriel would start filling him with hot and delicious cum – he'd feel that huge and sexy cock beating furiously against his insides – he would orgasm in sync with Asriel – it would be so perfect and and-

Asriel bleated out in ecstasy, hilting his shaft into Frisk way faster than Frisk had anticipated. The former human gasped and shuddered, eyes rolling back as he felt Asriel's viscous cum blast into him, the creamy white stuff coming out in huge gushes. The demonic goat grunted and huffed, pumping his brother full of royal seed, adding to the load already weighing Frisk's belly down. A lewd feeling of fullness spread from his slowly bloating belly, Frisk's hand trembling as it was mere inches away from touching that frantically throbbing dick, so, so close to having his release, wanting to feel his body get overtaken by a heavy orgasm while his brother was still filling him up…

Asriel grabbed Frisk's wrist just as his clawtips were about to touch the sensitive, flushed skin of his human-like shaft. With torturing slowness, the demonic goat pulled Frisk's hand further and further away from his needy manhood, the changed human whimpering helplessly, opening and closing his fingers weakly. He tried to beg for mercy, but his voice was too broken, too occupied with erratic panting and bleating to form any words. Frisk knew that Asriel was well aware of his anguish, though, feeling that kinky magic worming through his mind, unable to hold anything secret from his brother.

“Huff… Ruff...” Asriel grunted, pumping a few more gushes of spunk into Frisk before pulling out, shooting the last of his load all over the former human's back. He let go of Frisk's horns, stepping back from him, chortling in glee as he watching his exhausted brother collapse onto the sauna floor again, gasping for air, one hand on his swollen, cum-filled belly and other one weakly grasping his erection. The curse that Asriel had imparted on Frisk was still strong, keeping him from getting any kind of release without Asriel's help.

“My my... I don't think you've made me cum that hard in years, my dear brother. It must have been your helpless, broken begging.” Asriel continued as he climbed the pews again, already having regained his composure, sitting on the top seat, grinning down at Frisk as he lay there on the floor, curled up and on his side. Frisk bleated and whimpered pathetically in his desperation, locked on the very edge of a mind-numbing orgasm that he couldn't achieve on his own, no matter how hard he tried. He had a few tears rolling down his muzzle from how badly his dick and nuts were aching from all the teasing and stimulation, a red blush showing through all that white fur, Frisk's breath hitching. He was an utter mess.

“Baah… Aahsriel...” Frisk bleated with a defeated voice, spending considerable effort in just sitting up, one hand holding his swollen belly and the other still weakly stroking over his pre-squirting shaft in the vain hopes it would give him some relief. The need to cum was drowning out every other thought and need under it, Frisk feeling like every second spent without release was eating away at his intelligence, a bit of drool dripping down from his parted maw. “He… Help...”

“Mmh, aren't you entitled, my beloved brother.” Asriel chuckled, trailing a pair of claws over his softening dick, gathering mixed fluids onto them and flicking them at Frisk. “You know the rules. You only get to cum when I do. If you miss that window, well, that’s not my problem, is it? Although… I could make an exception, just this once.” Asriel stroked his chin theatrically, looking down at Frisk and considering the former human’s pleading, soulful expression.

Frisk tapped into his determination to get enough strength to move, kneeling in front of Asriel's legs, his breath still hitching and wheezing slightly, his shaft standing proudly from his crotch, brushing against the underside of his pudgy, cum-filled belly.

“I could let you use one of my feet...” Asriel began, lifting a foot up from the middle pew, slowly dangling it in front of Frisk, those glassy, vacant eyes instinctively following the paw as it moved. “...But at this point, such a privilege would be available only to those truly loyal to me.” He goat covered with natural tattoos continued, a sly smile on his face at the new game he had concocted. Frisk was desperate, he could see that. Perhaps this time... Frisk flinched as Asriel conjured an item, the small flash blinding his brother. Frisk blinked and shook his head slowly to clear his vision.

A black leather collar was dangling from one of Asriel's toe claws. It was held on the claw by its silver buckle. A small red heart tag on the collar clinked gently as Asriel waved it back and forth in front of Frisk’s nose.

“Wh… What…?” Frisk mumbled, gulping as he stared at the collar, then up at Asriel's grin, then back at the strap of black leather. He reached a hand up to his own neck, trailing a pair of claws along it thoughtfully. It felt strangely… Soothing, to feel something touch his neck. 

Gosh, it would feel so good if something…

...If that collar…

If that collar was around his neck. The thought flowed through Frisk’s mind like tar, consuming everything in its path. A mark of how much he loved his goat-brother, proof that he belonged to him, something that would always be there to remind Frisk of that...

“It would feel so right, wouldn't it, Frisk? To declare your devotion and love like that. Proudly wearing my collar around your neck.” Asriel spoke with a soft, affectionate tone, completely at odds with his predatory expression. Frisk hesitated, despite the enormous amounts of corrupt magic and fluids defiling his mind and body.Asriel patiently waved his foot back and forth, reminding Frisk of the price of his release. Each wag made Frisk's shaft bounce and spurt pre that his abused prostate was churning out in magically excessive amounts.

Frisk's fingers reached to take a cautious, shaky hold of the collar. He examined it briefly, feeling how smooth the black, unblemished leather felt against his fingers, before the former human tentatively looped it around his neck. It was a perfect fit. His eyes wandered around the sauna as he considered what he was about to do.

Frisk's gaze returned to Asriel, and he looked into his brother's eyes. With a sharp 'clink', Frisk buckled the collar around his neck.

Asriel grinned from ear to ear.

Frisk gasped in shock as he felt the collar pulse with some kind of magic, the buckle disappearing and leaving smooth leather behind. The collar became seamless around his neck, tightening slightly, the sense of tightness making Frisk shudder in twisted delight, his stubby, cum-stained tail wagging excitedly.

And then, he felt Asriel's foot press against his face. Another gasp left Frisk's maw, followed by a lustful bleat as he nuzzled into the hot, sweat-soaked pawpads. Once again, Frisk started to slather his brother's footpaw, trembling and moaning like a slut as he worshiped that paw.

And then, he felt Asriel's other foot against his dick. The tip slid between a pair of toes, that big, furry paw grinding down along the underside of that achingly hard and twitching shaft, Frisk's hips bucking on their own. His eyes were wide open, his hands grabbing Asriel's foot by its ankle and calf, the warped, defiled human panting wildly as he rubbed and ground his cock against his brother's foot. It felt so much better than anything he had ever experienced, Frisk humping that paw while slavering over the one against his face, completely lost in his deepest, darkest fantasies. The pressure that had been building inside of his loins peaked, and with a wavering bleat of nerve-searing pleasure, Frisk started to cum. The first rope of off-white spunk that blasted out was alone enough to put his normal orgasms to shame, the second spurt left his ears ringing and the world shaking. As the third wave washed over his body, Frisk passed out.

***

Frisk was frowning even though no one else was around. He was floating in the lake, on his back, a few inches from the pier, one of his curved horns hooked on one of the ladder's steps that were normally used to help swimmers get back up from the water. It kept him from drifting off further into the lake, keeping the transformed human nicely anchored in place. His internal clock told him he'd been floating for two solid hours already.

His ass still hurt. Fuck that, his everything hurt. Every step he'd taken after waking up had been shaky and unsteady. Asriel had had the decency to drag him back to the main cabin and toss him on a bed, but that was about it.

It had taken ages for him to clear out all the dried jizz from his fur which, as it turned out, tangled like crazy from anything that didn't have the consistency of water. He hadn't bothered to try finding one of Asriel's combs, so he'd just used his stubby claws to rip right through the clumps of fur. It had hurt like a bitch, doubly so when he'd cleaned the black streaks of fur going down his back. For whatever twisted reason, Az had left the skin hidden under the obsidian-colored fur really sensitive. Frisk was dying to hear what excuse his brother had for that.

Standing up hurt, and sitting was completely out of the question, possibly forever, but at least for another day or two. So, floating. The warm water was a nice middle ground.

Frisk stared up at the blue sky, sighing as he watched a bird fly overhead, leading his gaze gradually to the tip of his snout. His fucking snout. Still there, still real. He was still a goddamn goat. He was gonna kill Asriel. This was a messed up cherry on the fucked up cake.

Speaking of the goat hyperdevil, Frisk groaned as he heard the cabin door open in the distance, knowing that Asriel looking for him. Frisk had woken up before his goat-brother; Asriel tended to sleep heavily after a night of being the God of Hyperdeath. Even Frisk's furious bleats and the ruckus he'd made when he had stubbed a toe on a couch leg hadn't woken the snoring goatmonster up.

“H-howdy, Frisk.” Asriel called out to him as he stepped onto pier, cautiously walking towards the end. Asriel could just see a frown on Frisk's snout, watching as his brother reflexively curled up to protect himself, before having to spread back out to stay afloat. Asriel stopped a few feet away from Frisk, holding a rolled-up towel like some kind of offering.

“You, uh, forgot to bring a towel with you. So, I brought you one!” He continued, smiling sheepishly, cheeks burning with a blush. “I also put some tea on and-”

“Az. Turn me back.”

Asriel bit his lower lip, scratching his neck while looking to the side. “I, uhm...” He stammered, the blush on his cheeks getting brighter. “...I forgot how, Frisk.”

A moment of silence ensued.

Frisk grabbed a hold of the pier, pushing himself a bit further off into the water so that the pier wouldn't obstruct Asriel's view of his head. He had that peculiar neutral expression on his face, the kind where Asriel (or anybody for that matter) couldn't tell if Frisk's eyes were closed or not. It always bugged the shit out of Az, whom would have much preferred an angry frown over that creepy look.

“I-I mean, I sorta forgot! State dependent memory!” Asriel blurted as he tried to explain himself, awkwardly fidgeting as he stood there, hugging the big and fluffy towel roll against his chest. “I-I swear, I'll change you back as soon as I can! I'm certain that I can find a way switch to Hyperdeath mode and not, y'know. Get... weird.”

Frisk kept staring at him with that weird neutral face. Asriel was imaging what kind of anger was hidden beneath it, the fluffy goat always getting really anxious when he couldn't tell what people were thinking.

“A-and it's probably gonna fade away on its own, anyways! I mean, you're not really a monster, you just got the body of one. For now. Your Soul is still human.” He kept reassuring both Frisk and himself, nodding a couple times in a very forced way. “Actually, I'm sure! You'll turn back into a human in a couple days tops!”

Frisk lifted an arm out of the water, pointing wordlessly with a dripping claw at the seamless black leather collar around his neck. The fur surrounding it was too short to conceal it much at all.

“...Ah. Right. Uh… M-maybe we can just cut it off?”

Frisk made a point of pinching and clawing at the black strap of leather. He could barely fit the tip of a claw under it, the collar sitting so perfectly around his neck. And since it seemed to be composed of some enchanted material, Frisk couldn't so much as leave a mark on it.

“Oh. I guess that explains the broken scissors on the kitchen table.”

Another moment of silence followed. Asriel kept squirming under Frisk's gaze. Was Frisk mad at him? Was he disappointed in him? Come to think of it, that probably was Frisk's plan, keeping Asriel guessing.

Asriel swallowed hard, toes anxiously tapping the wooden boards. He was desperately trying to come up with something to lighten the mood. Frisk's expression remained unchanging. “But hey, at least now you have your own horns to file… And… groom… Uh, Frisk?”

While Asriel was speaking, Frisk had gradually dipped further underwater. By the time Az called out for his name, only the last inch of his right horn remained above the surface. A moment later it sunk as well, Frisk managing to slip from Asriel's sight as he swam off to somewhere.

“Fr-Frisk?” Asriel called, peering around the water surrounding the pier, trying to catch a glimpse of his brother. He couldn't even see anything disturb the water's surface as he stepped from side to side on the pier.

“Frisk! I'm sorry! I’m really, reall-”

And as he said that, Frisk suddenly resurfaced in front of him. Well, more like leaped up from the water, clearly having built some momentum for the attack. While still in the air, Frisk grabbed Asriel's horns, the goat's eyes going wide as he realized he was about to get pulled into the water. He bleated in terror, Frisk smiling smugly as he took his brother down under with him.

As soon as Asriel was underwater Frisk let go of his horns, fighting off a burst of laughter since having one while diving wasn't the healthiest idea. He had both hands covering his smirking muzzle as he watched Asriel squirm and fidget in the water, trying to find which way was up, the poor thing always having trouble with diving, the royal prince looking absolutely terrified. Frisk finally broke into hysteric laughter when Asriel's burbling bleats carried through the clear water, the former human swimming up and grabbing the pier for support. He shoved a leg against Asriel's chest so that he had something to orient himself by, the panicking goat grabbing onto it and then climbing up along Frisk's body to reach the surface.

Asriel emerged with a massive coughing fit, clearing out water from his lungs. Frisk didn't hold back his schadenfreude-laden laugh at all, climbing onto the pier and helping Az up. Doing so reminded him of how sore his rear was, putting quite the dent in Frisk's glee. In the end, Frisk simply helped Asriel up onto the pier and then slipped back into the lake himself, a smug smile still on his face. Sure, he was pissed at Asriel for messing around with his body to such an extent, but Frisk wasn't the kind of a person to hold grudges.

It took Asriel half a dozen coughs to clear out his lungs and throat, cheeks glowing like hot coals, the formerly fluffy fur now all matted and dark from all the water his pelt had absorbed. His t-shirt and baggy pants were just as drenched, and the towel he'd been carrying was drifting on the water, heading towards the shore.

Asriel looked like he was gonna shout at Frisk for doing that, but swallowed his words when Frisk pointed at his collar. That alone would be Frisk's trump card to justify anything he did to Az for months.

“Look, I'm really sorry, Frisk.” Asriel said with a sigh, rapidly shaking his head from side to side to shake off some water. While Asriel seemed to be really weird about getting his fur wet, Frisk was owning it, chilling in the water just as casually as he had when he'd been human, heavy wet fur or not. Asriel was still blushing, but the meek and bashful look was changing to a coy and playful smirk. “...Although, from what I remember, it wasn’t just me having a good time last night...”

Frisk huffed and splashed some water on Asriel, the already sodden goat just chortling and leaning back a little in a token attempt at dodging it. “I mean, all I wanted was to blow off some steam, something quick and casual… Well, as casual as I can be, in that form.” He continued, sticking his tongue out to tease Frisk. The collared goat huffed again, sinking up to his eyes to hide a blush on his white-furred cheeks. “But, when I started rifling through your thoughts... Golly, Frisk! I couldn't just say no to all that! You really are the, uh, the catalyst, I think? You cause nearly everything I do to you.”

The tide had turned again, it being Frisk's turn to feel all kinds of embarrassed and awkward. Thankfully he could hide almost all of it below the water, submerged up to the very top of his snout, leaving him able to breathe through his nose. His eyes were those unreadable black lines again.

“Honestly! I swear, I'm a really vanilla guy at heart. I mean, you never bring up my feet when we do stuff normally!” Asriel chuckled and kicked some water Frisk's way. The former human deftly avoided it by sinking and then slowly resurfacing, still keeping his burning cheeks hidden. “Although... That does explain your love for filing my toeclaws.”

“Hey! The collar was all you!” Frisk blurted, desperately trying to change the subject. He grabbed for the foot Asriel had kicked water with and pulled it under. For a moment, Asriel thought he was gonna get yanked into the water again, but instead he felt Frisk's claw-tipped fingers just gently holding his ankle and foot, the changed human glancing to the side, clearly uncomfortable to be touching it in light of recent events. But, Asriel noted, he wasn’t in a hurry to let go of it either. Something to think about.

“...I'll admit to that.” Asriel mumbled, attempting to ignore the soft caress against his rather ticklish pawpads for both their sakes.. “It… looksreallycuteonyouthough.” He continued with a brief whisper, tugging on his captured foot tentatively. Frisk's fingers were clutching it a lot harder after the whisper.

Yet another moment of silence followed, the awkwardness palpable in the air. Then Asriel looked like he got an idea.

“Hey, Frisk! C'mere.” He said, patting his wet lap, beaming. Frisk glared at him, Asriel's embarrased flush so hot that one could almost see water steaming as it evaporated. “I-It's not gonna be anything sexual, I swear!”

Frisk sunk further into the water suspiciously. Asriel smiled awkwardly and reached a hand out with the pinky extended. “Come on! I pinky promise!”

Jesus, 20 years old and still a complete dork. Frisk rolled his eyes, did the weird handshake thing and then climbed up, right onto Asriel's lap. He put his back against his goat brother's chest, the taller male's head resting on top of Frisk's. His ass still hurt a ton, making Frisk squirm impatiently.

“Just bear with me for a moment, okay? I promise this is gonna be good.” The monster prince said reassuringly as he took a gentle hold of Frisk's hands, palms against his currently goat-like brother's backhands, fingers sliding between Frisk's. Asriel spread both of their arms out like they were going to hug something. Frisk was getting curious about where this was going.

“Right, huh, how'd mum explain it… Try to focus on warm emotions, okay? Happiness, love, y'know.” Asriel instructed with a calm voice, Frisk feeling a weird fleeting tingling in his hands. Frisk rumbled apprehensively and Asriel tried to calm his brother down by rubbing the underside of his chin against the top of Frisk's muzzle.

“Shh… Keep focusing. You're feeling warm tingles and pinpricks in your fingertips, yeah?” Asriel asked, Frisk nodding slightly. “That's good! Keep thinking warm thoughts. Imagine a line going from palm to palm and focus your eyes right in the middle of it.”

Frisk did that, curiosity trumping his reluctance. He pictured a line going from one hand to the other, eyes staring at where he imagined the midpoint to be. The tingling and pinpricks turned into a pleasant warmth, as if he was holding his hands close to a hot stove.

And then, a small, pea-sized orb of fire appeared where Frisk was staring. He blinked, which made the tiny fire flicker, Asriel booping Frisk's snout with his chin to help him stay focused. The conjured fire grew bigger, becoming as big as a strawberry, then a potato. It felt a steady stream of warmth flowing through his arms and collecting into his fingertips, a happy smirk on his lips. His whole body felt soothingly cozy, even the numbing pain in his hind fading a good deal.

Huh. Was this what magic felt like?

Asriel slowly slid his fingers away from Frisk's, hands pulling away while Frisk kept the casting posture. The magical fire remained strong and bright, Frisk taking deep breaths as he tried his hardest to keep it going.

“Since you're part monster for the time being, might just as well enjoy some of its perks, right?” Asriel chuckled, clicking his claws and conjuring a ball of flame with close to no effort. “Monsters are great at magic. It feels really natural to us, as you might have noticed.” Az continued, his fireball slowly orbiting around Frisk's. Asriel's flame was burning steadily and gracefully while Frisk's flickered defiantly. “Careful, Frisk...”

Frisk gasped as his flame almost died all of the sudden, Asriel swooping in to the rescue by engulfing it with his own. Even though Frisk couldn't see his flame, he could feel it cradled inside Asriel's fireball, it filling the changed human with a strange and soothing warmth.

Asriel hummed a familiar tune softly, wrapping his arms around Frisk's waist gently. Frisk still had his arms out, keeping the flame burning within Asriel's flame, smiling contently. Asriel's head remained resting atop Frisk's, the two goat brothers watching their combined fires intently.

They stayed like that for a long while.

**Author's Note:**

> An anon requested the very talented Crybleat to draw a picture based on the magic training scene! And it looks absolutely fantastic! You can find it here: http://crybleat.tumblr.com/post/136441015160/x


End file.
